Actuator, safety device, and flying body

Abstract

There are provided an actuator that can be reduced in weight as compared with a related art while alleviating an impact at an activation, a safety apparatus that ejects an ejected object, and an aerial vehicle including the safety apparatus. A safety apparatus 100 includes an actuator 1 , a push-up member 15 that is pushed up in one direction by the actuator 1 , an ejected object 16 that is pushed up while being supported by the push-up member 15 , a bottomed cylindrical container 18 , and a lid 21 that closes an opening end of the container 18 . The actuator 1 includes a piston member 10 , a cylinder 14 that accommodates the piston member 10 and is provided with a bore 13 through which the piston member 10 protrudes outward at the time of activation, a base 2 to which one end of the cylinder 14 is caulked and fixed and that is attached to a center of a bottom inside the container 18 , and a gas generator 17 as a power source for moving the piston member 10 in the cylinder 14.

The invention claimed is: 
     
         1 . An actuator comprising:
 a piston member including a body and a rod extending between a first end and a second end, said first end of the rod is directly connected to the body and having a smaller diameter than a diameter of the body;   a tubular member loosely fitted around the first end of the rod in a state where one end of the tubular member is in contact with the body;   a cylinder having an inner wall extending along a longitudinal axis of said cylinder between a proximal end and a distal end of said cylinder, such that said cylinder slidably accommodates the piston member and the tubular member inside the cylinder;   a stopper member provided at said distal end of the cylinder and having a bore through which the piston member protrudes outward from inside of the cylinder at a time of activation, the stopper member limiting movement of the tubular member within the cylinder at the time of activation; and   a power source that is provided at said proximal end of the cylinder and generates power for sliding the piston member in the cylinder, wherein   the tubular member includes a material that plastically deforms and has a lower tensile strength than a tensile strength of the piston member and the stopper member, such that during activation of said power source, the tubular member collides with the stopper member and the tubular member is plastically deformed; and   wherein the tubular member and said inner wall of the cylinder are separated from each other by a predetermined distance or more so that the tubular member does not contact the inner wall of the cylinder when said piston member slides inside the cylinder and after the tubular member collides with the stopper member such that the tubular member is plastically deformed by substantially uniform compression.   
     
     
         2 . An actuator comprising:
 a sliding member including a body and a rod extending between a first end and a second end, said first end of the rod is directly connected to the body and having a smaller width than a width of the body;   a tubular member provided around the first end of the rod in a state where one end of the tubular member is in contact with the body;   a cylinder having an inner wall extending along a longitudinal axis of said cylinder between a proximal end and a distal end of said cylinder, such that said cylinder slidably accommodates the sliding member and the tubular member in an inside of the cylinder;   a stopper member provided at said distal end of the cylinder and having a bore through which the sliding member protrudes outward from the inside at a time of activation, the stopper member limiting movement of the tubular member within the cylinder at the time of activation; and   a power source that is provided at said proximal end of the cylinder and generates power for sliding the sliding member, wherein   the tubular member includes a material that plastically deforms and has a lower tensile strength than a tensile strength of the sliding member and the stopper member, such that during activation of said power source, the tubular member collides with the stopper member and the tubular member is plastically deformed; and   wherein the tubular member and an said inner wall of the cylinder are separated from each other by a predetermined distance or more so that the tubular member does not contact the inner wall of the cylinder when said piston member slides inside the cylinder and after the tubular member collides with the stopper member such that the tubular member is plastically deformed.   
     
     
         3 . The actuator according to  claim 2  wherein a tapered portion is provided inside an opening of the tubular member on a side colliding with the stopper member. 
     
     
         4 . The actuator according to  claim 2  wherein
 a sealing member that has a ring shape and abuts on at least a part of the sliding member is provided on a part of an inner wall surface of the bore, and 
 at least a portion of an outer surface of the sliding member that contacts and rubs against the sealing member when the sliding member is assembled has a smooth shape. 
 
     
     
         5 . A safety apparatus comprising:
 the actuator according to  claim 3 ;
 a push-up member including a bottomed cylindrical portion disposed to cover at least a part of the cylinder, the push-up member including a flange-shaped portion that protrudes outward from an opening or a middle portion of a side surface of the bottomed cylindrical portion, the push-up member being pushed up in one direction by the sliding member; and 
 an ejected object that is pushed up while being supported by the flange-shaped portion of the push-up member. 
   
     
     
         6 . An aerial vehicle comprising the safety apparatus according to  claim 5 , wherein the ejected object is a parachute or a paraglider.